this is esp. useful for v6 hosts, where your provider might give you a changing prefix (we assume /64), but your interface ids stay the same.
but same mechanism also principally works for v4 (we assume /29), except that you usually do not get a v4 network where the network address is changing.
and when it comes to dynamic addresses, many people only get 1 ipv4 address anyway. the related host could then be used for aliaseses with ifid == 0 for all aliases.
as we first check for a nochg update, we couldn't always get the expected dnserr here as the dns update is tried after the nochg check.
so, if the address did not change, the test failed. fixed by making sure it is not a nochg update.
Very similar to /nic/update and /nic/update_authorized, /nic/delete and /nic/delete_authorized delete
the A or AAAA record, depending in the kind of IP address given.
As this is a delete, the specific ip address value is ignored.
for the dnstools tests, tests were already changed to use a random test host in the test zone,
so parallel tests runs should not use the same hostnames.
test_api tests still use same host names, though
we do not really need it as far as the service is concerned (we would give some other valid failure result code),
but it might help to user to more quickly find the mistake in his client configuration.
generate_secret was modified to support giving a secret (not generating a random one), so it matches the test database
add a User and a Host to the test db